Exports K2 comments to be imported into Disqus (Wordpress format)

k2commentexport.php

<?php

// Turn off all error reporting
error_reporting(0);

/**
 * Constant that is checked in included files to prevent direct access.
 * define() is used in the installation folder rather than "const" to not error for PHP 5.2 and lower
 */
define('_JEXEC', 1);

define( 'DS', DIRECTORY_SEPARATOR );

if (file_exists(__DIR__ . '/defines.php'))
{
	include_once __DIR__ . '/defines.php';
}

if (!defined('_JDEFINES'))
{
	define('JPATH_BASE', __DIR__);
	require_once JPATH_BASE . '/includes/defines.php';
}

require_once JPATH_BASE . '/includes/framework.php';

// Mark afterLoad in the profiler.
JDEBUG ? $_PROFILER->mark('afterLoad') : null;


//Set the domain we're going to import to (no trailing slash). If blank the current domain will be used
$site = '';

// Instantiate the application.
$app = JFactory::getApplication('site');

$config = JFactory::getConfig();

$siteTitle =  $config->get('sitename');

if ($site == '') {
	$site = JURI::base();
}

$site = rtrim($site, '/');

//import the k2 router to construct the urls
require_once(JPATH_SITE.DS.'components'.DS.'com_k2'.DS.'helpers'.DS.'route.php');

// Get a db connection.
$db = JFactory::getDbo();

// Create a new query object.
$query = $db->getQuery(true);

// Select all items with the needed parts to create the urls and the post title
$query
->select(array('a.id', 'a.alias', 'a.catid', 'a.title'))
->select($db->quoteName('b.alias', 'catalias'))
->from($db->quoteName('#__k2_items', 'a'))
->join('INNER', $db->quoteName('#__k2_categories', 'b') . ' ON (' . $db->quoteName('a.catid') . ' = ' . $db->quoteName('b.id') . ')')
->order($db->quoteName('a.id') . ' ASC');

//$query->setLimit('400');

// Reset the query using our newly populated query object.
$db->setQuery($query);

// Load the results as a list of stdClass objects.
$items = $db->loadObjectList();

$xmlItems = array();
//Loop through the posts and get the associated comments
foreach ($items as $item) {
	$query = $db->getQuery(true);
	$query
	->select('*')
	->from($db->quoteName('#__k2_comments'))
	->where($db->quoteName('itemID') . ' = \''.$item->id.'\'')
	->order($db->quoteName('id') . ' ASC');
	$db->setQuery($query);
	$comments = $db->loadObjectList();

	if ($comments){
		$itemLink = urldecode(JRoute::_(K2HelperRoute::getItemRoute($item->id.':'.urlencode($item->alias), $item->catid.':'.urlencode($item->catalias))));
		$itemTitle = $item->title;
		$item = "\t\t".'<item>'."\n";
		$item .= "\t\t".'<title>'.$itemTitle.'</title>'."\n";
		$item .= "\t\t".'<link>'.$site.$itemLink.'</link>'."\n";
		foreach ($comments as $comment) {
			$item .= "\t\t\t".'<wp:comment>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_id>'.$comment->id.'</wp:comment_id>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_author><![CDATA['.$comment->userName.']]></wp:comment_author>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_author_email><![CDATA['.$comment->commentEmail.']]></wp:comment_author_email>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_date>'.$comment->commentDate.'</wp:comment_date>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_date_gmt>'.$comment->commentDate.'</wp:comment_date_gmt>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_content><![CDATA['.$comment->commentText.']]></wp:comment_content>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_approved>'.$comment->published.'</wp:comment_approved>'."\n";
			$item .= "\t\t\t\t".'<wp:comment_parent>0</wp:comment_parent>'."\n";
			$item .= "\t\t\t".'</wp:comment>'."\n";
		}
		$item .= "\t\t".'</item>'."\n";
		//push into the items
		$xmlItems[] = $item;
	}

}

// Output XML header.
$xml = '<?xml version="1.0" encoding="UTF-8" ?>' . "\n";
$xml .= '<rss version="2.0" xmlns:excerpt="http://wordpress.org/export/1.2/excerpt/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:wp="http://wordpress.org/export/1.2/" >' . "\n";

// Output root element.
$xml .= '<channel>'."\n";
$xml .= '<title>'.$siteTitle.'</title>'."\n";
$xml .= '<link>'.$site.'</link>'."\n";

// Output the data.
if(!empty($xmlItems)){
	foreach ($xmlItems as $xmlItem){
		$xml .= $xmlItem;
	}
}
// Terminate root element.
$xml .= '</channel>'."\n";
 // Terminate rss element.
$xml .= '</rss>'."\n";

header('Content-disposition: attachment; filename=k2_comment_export.xml');
header ("Content-Type:text/xml; charset=utf-8"); 
//output the XML data
echo  $xml;

header("Expires: 0");

As well is there a way to change the SQL query to filter from a category?